Mining machine



Feb. 14, 1956 F. CARTLIDGE ET AL MINING MACHINE 6 Sheets-Sheet l Filed NOV. 6. 1951 Feb. 14, 1956 F. CARTLIDGE ET AL MINING MACHINE 6 Sheets-Sheet 2 Filed NOV. 6. 1951 m e e llll I- www @hd N N WW Zi?,

MINING MACHINE 6 Sheets-Sheet 3 Filed Nov. 6. 1951 mmm NNN BNN RMN m e m Nww wh wm w N N gf u mmm .d :I ri d 5 ab d c :La M4 mw www nm mm NN mm Qmm mm w @ed Feb. 14. 1956 F. cARTLlDGE r-:TAL 2,734,731

MINING MACHINE Filed Nov. 6. 1951 6 Sheets-Shea?l 4 @i w INVENTORS N 1 l@ Earzk Uarlidge N FrankALindgre/z ATTOQNEY Feb. 14, 1956 F. CARTLIDGE E-r AL MINING MACHINE 6 Sheets-Sheet 5 Filed Nov. 6, 1951 im m j. mmh wf@ www .mq o o o o.. wm www NN mmm i To Ela/1l.: Q/allidge Fea/zh Al/zndgren BY y @ZUM-w y 2 TTORNEy W um. mm ,wh

Feb. 14, 1956 F. CARTLIDGE ET AL MINING MACHINE 6 Sheets-Sheet 6 Filed NOV. 5. 1951 NVENToRs ankmllidge Frank Abndgren Y 77 ATTORNEY United States Patent() assignors to Goodman Manufacturing Company, Chicago, Ill., a corporation of Illinois Application November 6, 1951*, Serial No. 255,058

' s cleans. (ci. 26z7) -This invention relates to improvements in mining machinesad'aptedto remove coal or similar material from the face of the mine. More particularly, the invention relates to mining machines of the type having a plurality of laterally spaced boring heads including radial boring arms adapted to cut contiguous bores in advance of the machine, and wherein the circular bore pattern is modiled to produce flat floor and roof surfaces by means of two auxiliary cutter bars which follow immediately behind the radial boring arms.

Oney of the principal objects of the present invention is to provide a machine of the character above described having suiicient iiexibility and maneuverability in mining operations for cutting entries and rooms of considerably greater widththan the normal span' of the cutting elements by advancing said cutting elements'in various angular directions relative to the main body of' the machine.

A further object of the invention is to provide means forI varying the angle of generally horizontal advance of thecutting' elements so a's to follow uneven or rolling bottoms or veins;

Other'objects and advantages of the invention will appear from time toY time a's the following description proceeds.

The invention may best be understood by reference to the accompanying drawings, in which:

Figure 1 is a plan view of a machine embodying our invention, showing it in a working position in a mine entry or room; v

, Figure 2 is a side view of the machine shown in Figure 1, withpart's shown in section;

Figure 3 is an enlarged, fragmentary plan view' of' the frontend or cutting head of the machine shown in Figure 1, with parts of the mechanism shown in section;

Figure 4 is an enlarged front view of the machine;

Figure 5 is a section taken generally on line 5-5 of Figure 3 and drawn to the same scale as Figure 4;

Figure 6 isa detailed side view of the front end of the machine, drawn tol a larger' scale than Figure 2 and showing certain' parts thereof in" section;

Figure 7 is an enlarged horizontal detailed section of Athe gathering conveyor at the front end of the machine;

vFigure 8 is a detailed section taken on line 8 8 of Figure 7, but drawn to a somewhat reduced scale;

Figure9 is a perspective view of the gathering conveyor, details of which are vshown in Figures 7 and 8; Figure' 10 is a detailed side view of the cutter head, drawn to the same scale as Figure 6v and indicating in dotted lines the manner in which the cutter head is v'capable of being projected forwardly for a boring operation and also indicating the manner in which the cutter head is capable ofbeing adjusted vertically so as yto change the pitch or incline along which the machine is advanced;

Figure-1 1 is an enlarged detailed section taken on line 11'-11 of Figure 10;

Figure 12 is a detailed section taken on line 12--12 of Figure 5.

Referring now to details of the 'embodiment of our in- 2,734,731 Patented Feb. 14, laas ICC ventionl illustrated in the drawings, a mobile base indicated generally at 9 is mounted on endless treads 10 10 and has a cutter head, indicated generally at 11, at its front end comprising essentially a pair of boring heads including radial boring arms 12, 12 rotating onv parallel longitudinal. axes, and a pair of vertically spaced parallelA cutter bars 13 and 14 disposed immediately to the rear of the common plane of rotating movement of the radial boring arms12, 12. The mobile base 9 shown herein is of-the` same general construction heretofore employed in continuous mining machines of the kind. shown in the copending application of Frank Cartlidge, Serial Number 116,684, :tiled September 20, 1949, the main features of which may be briefly mentionedas follows:

The main framek indicated generally at 1-5 has suitable drive means (not shown) for the endless treads 10, 10 for operating them in unison or at dillerent speeds' in opposite directions for maneuvering the machine as usual on the mine floor. The cutter head 11 with its cutting elementsv is mounted for forward thrust and retractive movements atv the front end of a subframe 16, the rear end of which-'is supported on a turntable 17 having its center of rotation on a vertical axis A-A.

Further description of the turntable mounting for the subframe 16 on the main frame may be omitted'since it may be the same as that disclosed inthe application, Serial Number 116,684, previously mentioned.

An endless conveyor, indicated generally at I8,` is mounted centrally' alongthe main frame to gather loose material from along the groundl at the rear of the cutting head, 'and carry' it upwardly and thence rearwardly-along the top of the machine for discharge into mine cars or other material-transporting means at the rear of the machine. Those portions ofthe conveyor 18 which carry the material along and rearwardly of the machine frame may be of the same construction disclosed in the copending application, Serial Number 116,684, above referred to, and includes an articulated joint, indicated at 19, to permit lateral swinging movement of the cutter head as a whole about' the vertical axis A-A.

The conveyor also has a second articulated joint indicated generally at 20, permitting lateral swinging movement of a rearwardrnost discharge section 21 of the con'- veyor about an upright axis BB.

The conveyor 18 is of the endless type, including a sing'le central chain 22 of conventional form, having a plurality of transversely extending ilights 23, 23 in spaced relation thereon. The conveyor structure also includes a take-up mechanism for the lower or return reach of the conveyor' chain, as indicated at 25 in Figure 2. This takeup mechanism may be of the same construction shown in a copending application, Serial Number 236,548, which has matured into Patent No. 2,642,981 dated June Z3, 1953, and is employed to permit shortening or lengthening ofthe front end of the conveyor chain during forward thrust or retractive movements of the cutter head relative to the sub frame 16, as will hereinafter be described. The subframe 16 has a pair of laterally spaced trunnions 26 extending forwardly thereof, between whichy an intermediate frame 27 is pivotally mounted for limited vertical swinging movement. The trunnions include a pair of opposed hollow studs 28, 28 projecting inwardly therefrom Aon which the intermediate frame 27 is journalled. The intermediate frame 27 has laterally spaced guide railsv 29, 29 txed at opposite sides thereof disposed beyond the front ends of the trunnions 26, along which guide members or gibs 31, 31 of an extensible frame 32 are slidably mounted. The extensible frame 32 provides vthe main bearing support for the radial arms 12, 12 and the cutter bars 13 and 14 of the cutter head.

The extensible frame 32 is extended or retracted by power relative to the intermediate frame 2'7 by means of a pair of laterally spaced hydraulic cylinders 33, 33, each having their rear ends connected to an arm 34, herein formed rigid with and extending rearwardly from the lateral extensions 29 of intermediate frame 27. The piston rods 35 of the hydraulic cylinders 33 are connected at their forward ends to lugs 36, 36 formed integrally with the extensible frame 32.

The hydraulic cylinders 33, 33 are of conventional double-acting type to advance or retract the extensible frame 32 with its cutting devices relative to the intermediate frame 27.

Vertical swinging movement of the intermediate frame 27 and the extensible frame 32 is produced by a pair of laterally spaced hydraulic cylinders 39, 39, each having their front ends pivoted to upstanding lugs 40, 40 formed integrally with the intermediate frame 27. The piston rods 41 of cylinders 39 are pivotally connected to lugs 42 formed integrally with the subframe 16. The hydraulic cylinders 33,33 and 39, 39 are actuated as usual from any suitable source of hydraulic pressure (not shown) under control of the operator.

Each of the cutting arms 12 comprises an elongated tubular member S0, herein shown as generally rectangular in cross section, rigidly fixed at its center to a main drive shaft 51 disposed at right angles thereto. Each arm supports a plurality of forwardly and inwardly and outwardly projecting cutting elements for cutting a plurality of circular kerfs as the two arms are rotated on their respective shafts 51. In the form shown herein, two pairs of such kerf cutting elements are provided, the inner pair consisting of generally L-shaped cutter brackets 52, 52 fixed at their rear ends to the front faces of the arms, and having a plurality of cutter bits 53 detachably secured in cutting position at their front ends in any suitable manner.

The outer pair of cutter brackets 54, 54 have their inner ends secured integrally with tubular members 55 closed at their outer ends and telescopically mounted in the opposite ends of arms 12 for radial extension and retraction. In the form shown herein, each of the outer cutter brackets 54, 54 have an outwardly offset terminal portion 56 provided with a plurality of detachable cutter bits`57 at their inner and outer faces, and also a plurality of detachable cutter bits 58, S secured along their leading edges, so as to extend forwardly and radially with respect to the entire rotating assembly formed by the rotating arms 12 and their forwardly projecting cutter brackets 52 and 54.

Each cutter arm 12 is also provided with a tapered drill-like member 69 projecting forwardly concentric with the drive shaft 51 and having terminal cutter bits 61 projecting slightly in advance of the cutter bits 53 and 5S of the cutter supports 52 and 54 on cutter arms 12.

The main drive shafts 51, 51 of the two cutter arms 12 pass rearwardly through si-milar intermediate gear housings 59, 59 having antifriction bearings 62, 62 for said shafts at the front ends thereof. The rear ends of the two shafts 51 are splined at 63 in the front ends of hollow splined sleeves 65, 65. Said sleeves are rotatably supported in antifriction bearings 66 and 67 at opposite ends of hollow bearing members 68 formed integral with the extensible frame 32. Retaining plates 64, 64 are secured to the rear ends of the shafts 51 in abutting relation with the internal spline at the front ends of the hollow sleeves 65.

As will be seen in Figure 3, the rear ends of the intermediate gear housing 59 are fixed to and enclose the front ends of the hollow bearing members 63. A pair of splined shafts 69, 69 extend into the rear ends of the sleeves 65, 65 and are fixed in the front ends of hubs 70 of spur gears 71 rotatably supported on the intermediate frame 27 as by spaced antifriction bearings 72, 73.

The spur gears 71 are meshed with pinions 74, 74 on shafts 75 having bevelled gears 76, 76 xed thereon. Said bevelled gears are meshed with bevelled pinions 77, 77 on similar shafts 7S, 78, each of which extends outwardly and concentrically through one of the hollow studs 28 of the trunnions 26 at one side of the subframe 16, as previously described.

Power to the cutter head 11 and cutter bars 13 and 14 is provided by motors 80--80 and their respective gear drives indicated generally 81; said drives having been fully illustrated and described in the previously-mentioned application, Serial No. 116,684, which includes a slip clutch 82 to relieve overload conditions at the cutter head.

The mechanism for extending or retracting the outer cutter brackets 54 on the opposite ends of each cutter arm 12 includes a pair of hydraulic cylinders 90, 90 having their inner ends connected to a block 91 which forms an extension of the main shaft 51 within the hollowed portion of said arm. Said hydraulic cylinders extend centrally within the tubular telescoping sleeves 55 and have piston rods 93 connected at their outer ends to transverse ribs 94 at the outer ends of said sleeves 55. A tension coil spring 95 surrounds each of the hydraulic cylinders 90 with their inner ends connected with the block 91 aud their outer ends connected with the transverse rib 94. Said coil springs are normally maintained under tension, tending to hold the extensible sleeves 55 into retracted position. Under usual operating conditions however, the cutter supports 54 are forced outwardly to fully extended position by iluid pressure conducted to the cylinders 90 through branch conduits 96, 96 of a hydraulic supply duct 97. The last-named hydraulic duct 97 is passed concencentrically through and along the drive shaft 51 and into the front end of the splined shaft 69 where it is formed in a coil 98 enclosed within the opposite ends of the splined shaft 69 as by end plates 99 and 100. The supply duct 97 passes through the rear end plate 99 concentrically therewith to a suitable rotating pressure joint of conventional forrn, indicated at 101. In the form shown herein, said rotating pressure joint is mounted within a cup-shaped support 102 fitting within the enlarged rear end of the hub of spur gear 71. From the pressure joint 101, the pressure duct is continued rearwardly to a suitable pressure supply and control means (not shown).

The coiled portion 98 of the pressure supply duct 97 permits extension and retraction of the extensible frame 32 with respect to the intermediate frame 27 to the degree permitted by the coaction of the supporting rails 29 and the guide members 31, since the duct 97 is free to slip longitudinally through the front cover plate during any extension or retraction of the extensible frame 32.

Referring now to the construction and arrangement of the horizontally disposed cutter bars 13 and 14, details of these bars are shown in Figures 4 and 5. Since the structure and arrangement of both the upper and lower cutter bars is substantially identical, like reference characters will, in most instances, refer to both.

The lower cutter bar 14 consists of two end sections and a central section 111, each cylindrical in form and having a plurality of cutter bits 112 detachably secured therealong in endwise spaced staggered relation. The end sections 110 also have a plurality of endwise projecting cutter bits 113 and 114 mounted thereon at varying outwardly inclined angles to the axis of the roller as shown in Figures 4 and 5.

Each of the end sections 110 of cutter bars 13 and 14 are connected to the central section 111 by a reduced shaft 115 supported by antifriction members 116, 116 and a gear housing 117. As will be seen from Figure 5, the two pairs of gear housings 117 for the upper and lower cutter bars 13 and 14 are disposed along vertical planes substantially coincident with the drive shafts 51 for the cutter arms 12 and are upper and lower extensions 118 and 119, respectively. Each of said extensions includes an integral hollow sleeve 113 which is slidably mounted on the outer ends of a sleeve 119 formed integrally with the adjacent intermediate gear housings 59.

The geared drive'connections between the drive shafts 511, v51 'and the cutter bars 13 and 14 will-hereinafter be more fully described.

Each pair of gear housings 117, 117 which support the upper and lower cutter bars 13 and 14, respectively, are rigidly connected together by yokes 129, the inner ends of which are connected integrally with hydraulic cylinders 121, 121 disposed in a vertical plane coincident with the longitudinal axis of the machine. Each of the cylinders 121 has a piston 122 therein carried on o'ne end of a vertically disposed piston rod 123 xed to a cross bar 12'4 connecting the two intermediate gear housings 59. Pressure is supplied to opposite sides of the cylinders 121 through suitable pressure supply lines (not shown) for raisingor lowering thevcutter bars 13 and 14 relative to the extensible frame 32, as desired.

As willbe seen in Figure 4, the axes of rotation of the two radial arms 12, 12 are laterally spaced so that their outer ends rotate in coplanar overlapping paths along the center of the cutter head. In order to synchronize the rotation of said radial arms to avoid interference between them, the main drive shafts 51, 51 for said arms have geared interconnection with eachother through common drive connections for rotating the two cutter arms, as shown in Figure 5.

Each drive shaft 51 has a bevel gear 125 lixed thereon within gear housing 59 and meshed with similar bevel gears 126, 126. The latter gears are fixed to the inner ends of splined shafts 127, 127 which extend upwardly and downwardly into splined engagement with the hubs of bevel gears 128, 128 in the upper and lower gear housings 117 in which the two cutter bars 13 and 14 are journalled. The bevel gears 123, 128 are meshed with bevel gears 129, 129 fixed on the horizontal shafts 115l ofsaid cutter bars.

As will be further observed by the arrows in Figure 5, the main drive shafts 51 of the rotary arms 12 are preferably driven in opposite directions to each other, while the two cutter bars 13 and 14 are also preferably driven inopposite directions to each other. Accordingly, the bevel gears 129, 129 are disposed on their respective shafts 115 solas to drive the cutter bars 13 and 14 in the proper reversed directions, and at vthe same time complete the desired geared interconnection between the drive shafts 51, 51 to maintain a dilference in phase of approximately 90 degrees between the two boring arms 12, 12 at all times, as will be seen in Figure 4.

Referring now to the means for collecting the cuttings as they are removed from the working face, the conveyor chain 22 o-f the conveyor 18 has its front end trai-ned about a roller 130 carried adjacent the front end of a gathering hopper, indicated generally at 131. Details of this gathering hopper are shown in Figures 7 to l0, from which it will be seen that said hopper has an outwardly ared front portion extending the full width of the bottom cutter bar 14, with a receiving lip 132 provided with toothed projections 133, 133 in transversely spaced relation to provide clearance for the cutter bits 112 mounted on the lower cutter bar 14. The gathering hopper 131 is piv-y otally secured to the rear of the lower bearing supports 117 as by ears 134 projecting rearwardly from said bearing supports and pivoted by pins 135 to ears 136 fixed to the under side of the lip 132 o-f the gathering hopper. The teeth 133 along the gathering lip afford clearance for the cutter bits 112 and extend into close gathering rela-v tion with the sections 110 and 111 of the lower cutter bar 14 in all positions of movement of said lower cutter bar.

Theupright side walls 137 of the gathering hopper 131 are integral with a bottom pan 138 and an intermediate pan 139 spaced above said bottom pan. The intermediate pan 139 is designed to support the upper flight of the conveyor chain 22 along its upper surface. The end roller 130 for said conveyor chain is journalled trains versely along the front end ofrsaid intermediate pan, as shown in Figure 7. The terminal edge of the intermedi- 6 ate' pani 139 is" disposed at substantially the Nsamelevelas the gathering lip 132 at the frontend of thegathering hopper, and the bottom pan 138 is curved vdownwardlyk and then rearwardly in spaced relation to the intermediate pan 139 to provide av space `for passage of the conveyor chain around the endroller 130.- l

The gathering hopper 131 is telescopica-Uy mountedwith respect to a rearward extension of the gathering hopper, indicated at 145, and having sidewalls 140,.:1- bottom pan 141 and an'upper pan 142.- Said rearwardextension is hinged to a downwardly inclinedv-seetion- 150 of the main conveyor 18, andthe adjoining con; veyor sections 145 and-'150 are mutually supported onpivot pins 1-46 carried on a pair of laterally spaced'supporting arms 147, 147 depending from and-` rigid with the subframe 16. The depending arms 147lthus--provide a rigid support for the downwardly linclined section 150 ofthe main conveyor 18. l

Suitable guide strips 151 and 152 are mounted along the side walls of the downwardly inclined-[conveyor see-Y tion 150 as hold-down means for the ends ofthe conveyor flights 23 as they pass between the steeply, inclined conveyor section 150 andthe less inclined conveyory section 145. By reason of the hinged connection of the two conveyor. sections 145 `and 150 and the telescopic connec; tion between the conveyor section 145 and the gathering hopper 131, said gathering hopper is free to swing. ver-A tically and also to be extended or retracted forwardly andy rearwardly ,as required to Amaintain its receiving lip 13 2 in substantially the same cooperative relation with the lower cutter bar 14--in all permissible positions of adjustment thereof, as will hereinafterA be more-fully described.- i l Y Y Y Each of the boring arms 172, 12 may be provided with suitable corebreakingrollers 155 supportedon brackets Y156 in position to follow the circular kerf cut by the inner pair of cutter brackets 52, 52 but at an anglel to the latter so` as to lbreak awa-ythe adjacent circular cores as the cutter head advances into the working face.

*'E'achof the'rotary boring. arms V12, 12 may also be provided with a pairk of scoops 157r adjacent their outer ends and on thefad-vance edge thereof, in posit-ion to sweep the cuttings dislodged Afrom the working face by the operation of said boring arms toward the center of the gathering hopper 131. .d j i As-shown in Figure 12, each of they cylinders .1121 has a vertical V-shaped iinv along its front face, indicated at 159, to deilect loose coal as it is broken away fromthe coal face by the radial arms 12. 1' Y i A pair of endwise telescoping -retainirigfballies indicated at 160,- 160 are supported by struts 161, 1761., detachably connected to and extending laterallyfrom the outer sides of the extensible frame 32. Each of said retaining baflles consists of two spacedplates 162, v-163 lfixed between the outer ends of the upper and lower cutter bars 13 and 14, and on a-n'arc which is slightly greater than the maximum bore cfu-tby its adjacent boring arm 12' (see Figure 4). A plate 164 curved on Athe same arc is telescopically mounted for forward and retractive movementY between each set -of plates 162,. 163, and is normally urged into forward position by springs 165, 165 coiled on guide rods 166, eachhaving oneend xedvto a lu'g 167 on the outer face of themovab'leplate-d, and the other end slidably mounted in a lug 16.8' onthe outermost fixed plate 163 (see Figure 11.)'. The fixed plates 162, 163 extend forwardly approximately to a transverse plane coincident with the front faces of the rotary boring arms 12, 12, while the telescopic plates-164 can be extended therebeyond for substantially the length ofthe cutter supports 52, 54 on the boring arms', as' shown in Figure 1. I

The use and operation of the machine i's as f''llwfst d The machine is moved on its-endless tr'ads'lG-tnt position in a 'mine entry or' room, with the subfinie' 16 adjusted about the verticalaxis Ae-A at'al suitable angle t the working face, and with the extensible frame 32 which carries the cutter head 11 in its fully retracted position ready to attack the working face. In the working position shown in Figure 1, the subframe 16 and cutter head 11 are disposed for straight-ahead progress in alignment with the longitudinal axis of the machine, and at a right angle to the working face to be attacked. The treads are then locked against movement by any suitable braking means to hold the main frame against movement during the boring or cutting operation. Auxiliary roof and floor jacksmay also be used if necessary to hold the main frame in place. The boring arms 12,12 are rotated by the driving motors 80, 80 through the geared connections previously described, so that said boring arms rotate in opposite directions to each other.

Under normal cutting conditions, the outermost cutter supports 54, 54 which are telescopically adjustable longitudinally of the boring arms are disposed at their outermost positions, as shown in dotted lines in Figure 3. The upper and lower horizontal cutter bars 13 and 14 are adjusted so that their outermost cutter bits are normally in horizontal alignment respectively with the uppermost and lowermost limits of the circular kerfs bored by the outermost cutter supports 54 so as to modify the circular hole pattern produced by the boring arms to a generally rectangular cross section and, in particular, to leave at'tloor and roof surfaces, as indicated in Figure 4.

' The cutter bars 13 and 14 are simultaneously rotated as previously described through the interconnected drive gearing whichsynchronizes the rotation of the boring arms 12, as previously described. f

. vThe intermediate frame 27 is adjusted on its transverse axis with respect to the subframe 16 so as to extend along a longitudinal axis parallel to the mine floor, excepting in cases when it is desired to change the pitch of advance,

as will presently be described.

Hydraulic power is then supplied to the cylinders 33, 33 to project the extensible frame 32 and the cutter head 11 forwardly with respect to the intermediate frame 27 at a relatively slow speed suitable for forcing the cutter head as a whole into the working face of the mine.

The rotation of the boring bars 12 during this forward or feeding movement results in advancing the cutter supports 52 and 54to cut overlapping concentric ring-like kerfs in the coal face. Simultaneously, the tapered drills 60 on they Ycenters of the two boring bars are projected into the coal face at the centers of the concentric kerfs.

As the boring bars progress into the working face, they are followed by the upper and lower horizontal cutter bars 13 and 14 rotating in opposite directions to each other,v as indicated in Figure 4. As will be seen from this figure, the generally rectangular pattern thus produced bythe boring arms 12, 12 and the cutter bars 13 and 14 includes side walls of uneven but symmetrical shape, combining the outlines produced by the boring arms and the ends of the cutter bars 13 and 14. While the cutter head is being advanced into the coal to form the circular kerfs, as aforesaid, the tapered center drills 60, 60 are forced into the coal face, tending to break away the inner core left'between said center drills and the inner circular kerfs made by cutter supports 52. The wedge rollers 155 carried by the cutter arms aid in breaking down surrounding circular cores as the cutting progresses.

It will be observed that the radial boring arms 12, 12 cut circular` holes having their maximum diameters directly in advance of the twin bearing supports and drive connections to the upper and lower cutter bars 13 and 14, as clearly shown in Figures 4 and 5. In other words, the gear housings 117 which form the bearing supports for the horizontal cutter bars 13 and 14 are all in vertical alignment with the axis of rotation of the drive shafts 51, 51 of the two boring arms, and the telescopic drive connections between thetwo shafts 51, 51 and the horizontal cutter bars 13 and` 14 are also disposed in the same vertical planes at the point of maximum working diameter of the two boring arms.

During the forward feeding operation just described, the coal that is broken down from the working face by the boring arms 12 and also by the cutter bars 13 and 14 is deposited upon the front end of the gathering hopper 131 and will be removed therefrom by the conveyor ights 23 of conveyor 18 for discharge at the rear end of the machine. The scoops 157, 157 carried by the boring arms 12, as they are rotated downwardly and inwardly toward the center of the gathering hopper, aid in deflecting the cuttings from the boring arms inwardly toward the cutter of the gathering hopper 131. Due to the inwardly sloping side walls 137 of said hopper, loose material accumulating at opposite ends of the fathering lip will tend to be deflected toward the center of the hopper to be engaged and carried away by the conveyor.

After the extensible frame 32 and the cutter head 11 have been projected forwardly a predetermined distance into the working face, the movement of Avthe extensible frame is reversed by operating the hydraulic cylinders 33 in the opposite direction. The length of stroke of the forward feeding movement of the cutter head is preferably about the same as the length of the cutter supports 52 and 54 which project forwardly from the cutter arms 12. For instance, in a practical and satisfactory embodiment of my machine, both the forward stroke of the extensible frame 32 and the length of the cutter supports 52 and 54 are approximately eighteen inches.

The telescopic mounting of the cutter supports at opposite ends of each of the cutter arms 12 is provided primarily to aid the operator in breaking down the outermost core of coal which otherwise might be left projecting from the working face during each feeding operation and also to aid in removing or withdrawing the cutter heads from the drills at the conclusion of each feeding operation when necessary. It will be understood that considerable endwise bending stresses are usually imposed on the outer faces of the cutter supports 54 during forward feeding movement. The telescopic adjustment of these arms aids in materially withdrawing the cutter supports 54 from the bore at the conclusion of their forward movement. It will, therefore, be understood that, while the endwise telescopic movement of the outer cutter supports 54 might be utilized under some conditions for varying the effective lengths of the boring arms and thereby varying the vertical and horizontal dimensions of the bore being mined, yet under normal operating conditions, it is usually preferable to maintain the boring arms at substantially their maximum lengths, and thereafter retract the outer cutter supports relative to the boring arms to aid in freeing said boring arms from the bore at the conclusion of each forward cut.

Should a grade be encountered in the coal vein necessitating a grade cut, the cutter head 11 can be liftedor lowered (as seen in Fig. l0) by pressure to cylinders 39--39, to move the cutter head from its normal operative position as indicated by line C-D to a position as indicated by line C-E. The outward oset 56 of the radical cutter brackets 54 will cut a step in the mine iloor; the cutter bar 14 with its gang of bits 112 follows the cut and levels off said steps to define a substantially smooth floor and roof. Line C F represents the condition that exists when a series of such cuts are made to produce a steep grade, leaving a relatively smooth floor and roof line.

Under some conditions, it may also be found desirable to extend or retract the horizontal cutter bars 13 and 14 vertically so that either may cut at a slightly diiferent level, or may remove somewhat more or less roof or bottom than the normal cutting diameter of the boring arms 12. This can be readily accomplished by supplying fluid pressure at will to either or both of the hydraulic cylinders 119 which control the horizontal position of the upper and lower cutter bars 13 and 14.

The machine may be employed for cutting relatively p For'example', as s'nl in Figure 1 the entire-y working face irsintiicat'edv at FL-I; one segment Fe-G has' already heenremoved" bythe ria'cliirieA with thesub'rine lvdis'posed on a longlt'dinalaxis--Y Tfli'ef cutter head isl now'` s'liovv'nv i'na' second position with the' subfr'a'nie disposed-xl o`n `axis 5r-X,` to rmv' a'- second segment of the working face. Upon completion' of this operat'ipmthe sulfratrie 16 vvill b'eswng latraily into ajthird position on axis --Z, to Vrei'rzv's': the third segment H,-,.,T,thu`s completing' therefnova-l of the entire working: faceY with o'ii setting o`f` tle' riiain frame' the machine.

Thereafter, the yentir'c': machine may be moved forwardly on its treads a distance substantially equal to the more of the' erfeasinfrfne 32; am vsame succeseve boring operations at different angles to the face are repeated.

The telescopic bales 160, 160 at opposite sides of the cutter head 11 prevent lateral spillage of loose material as it is removed from the working face by the rotary boring arms, particularly in cases where the cutter head is presented to a segment of the working face in a position immediately contiguous to a previously formed bore. This condition is illustrated in Figure l, wherein the cutter head has previously removed the bored segment F-G at one side of the room, and is set for a new bore along the segment G-H. Under such conditions, the cuttings may tend to spill out of the open side of the new bore into the previously bored segment F-G, The telescopic plates normally project yieldingly into `engagement with the working face at opposite sides of the radial boring arms, at the start of each forward stroke of the cutter head, and are automatically forced rearwardly as the radial arms are fed into the bore. However, if the bore should be open at one (or both) sides thereof, the corresponding telescopic plate 164 will remain in forwardly extended position and enclose the otherwise open side of the bore, and thus deect all the cuttings downwardly to the gathering hopper 131 for removal by the conveyor.

Where a narrow entry or tunnel is to be bored to the same width as the cutter head, the side bales 16), 16) and their supporting struts may be removed, and the machine is progressed in step-by-step operations, moving the base frame forwardly after each forward and retractive movement of the cutter head a distance substantially the same as the stroke of the said cutter head. It will be understood that the vertical and horizontal dimensions of the cutting head are ample to form a tunnel large enough to accommodate the body of the machine.

Although I have shown and described certain embodiments of my invention, it will be understood that l do not wish to be limited to the exact construction shown and described, but that various changes and modifications may be made without departing from the spirit and scope of the invention as dened in the appended claims.

We claim:

1. In a mining machine, a mobile base, an intermediate iol een

with theintermediate frame; said pivoted:v section includ;

ing a telescopic," front e'nd portion having its front en'd pi'vo'tablyr supported onv the bearingmeansi for said'` trans-'1 verse cutter' bar', i'np'osition to' collect: cuttings from the lttei int all positionslvofN verticaland extensible adjustment thereof relativel to said' base;

2'. InV a mining machine,a mobile base, a" cutter yhead2 rho'unted onsaid base including a horizontallyA disposed? cutter support with@ cutting means thereon, said cuttery support being pivofally rnounted on!` said frame for ver-f tical swinging mt'nerne'ritl of said cutter head, a llighty conveyor' mounted on arid1 extending along said base for' discharging cuttin'gsatthe rear of the machine, and hav-'1 ing` a forward sectiorrpivte'd at its rear endy to said base*- o'ny an axis belowfth'e' pivotal axis of the cutter support, to permit' s'vvii'ngiigy movement of said pivOted' sectionrelative to said base, said pivotedfsection having itsfront K endL pivotally connectedv to? and'swingable vertically with said` cutter support, in' position to collect cuttingsfrom. tlie after in' all positions of vertical' adjustment of the cutter supp-'crt relative to saidy base.

3. In a mining machine a mobile base, a cutter head frame having a pair of boring heads with drive shafts disposed on laterally spaced horizontal axes and with radially elongated arms having cutter devices thereon for cutting contiguous bores in advance of the machine, a pair of axially elongated vertically spaced cutter bars rotatable on horizontal axes disposed generally tangentially to the upper and lower cutting limits of said cutter arms but spaced rearwardly of the circular paths of said cutter arms, said drive shafts being journalled in a pair of laterally spaced housings on said cutter head frame, and said cutter bars each being journalled in auxiliary bearings supported on said drive shaft housings by extensions projecting above and below said drive shaft housings and terminating within the upper and lower cutting limits of said cutter arms, and driving connections for said cutter bars including gears mounted in said drive shaft housings concentric with said drive shafts and driven from said cutter head frame, and operatively connected to gears on said cutter bars by vertically disposed shafts mounted on each of said extensions.

4. The structure of claim 3, wherein outer end portions of the cutter bars extend laterally substantiallly beyond their respective auxiliary bearings and beyond the upper and lower limits of the circular paths of the cutter arms, to complete, with the boring heads, a single bore pattern generally rectangular in cross section.

5. The structure in accordance with claim 3, wherein the bearings and gear connections for the upper and lower cutter bar are enclosed in auxiliary housings fixed on the ends of each of the extensions, and the auxiliary housings are also disposed within the upper and ,lower limits of the circular paths of the cutter arms.

6. The structure of claim 5, wherein the extensions and the connecting shafts disposed therealong each have intermediate telescopic portions, the upper and lower pair of auxiliary housings are each rigidly connected by a yoke disposed within the circular paths of the cutter arms, and power means is provided between the frame and each yoke for extending or retracting said yoke and the pair of auxiliary housings connected thereto.

7. In a mining machine, a mobile frame, a cutter hea supported on said frame, said cutter head including a boring head with a horizontally disposed drive shaft extending longitudinally of the machine and with a radially extending cutter arm having a cutter device thereon for cutting a bore in advance of the machine, a cutter bar horizontally disposed generally tangentially to the cutting limit of the cutter arm and spaced rearwardly of the circular path made thereby to cut asubstantially flat transverse surface, said cutter bar beingsupported on said frame transversely to eachside of a vertical plane common to the axis of said drive shaft, drive means for said cutter bar supported on said frame, and a driving connection between said drive means and said cutter bar connected to the cutter bar intermediate the ends thereof, said driving connection being disposed in said vertical plane and Within the cutting limitof the cutter arm.

8. In a mining machine, a mobile frame, a cutter head supported on said frame, said cutter head having a pair of boring heads with drive shafts disposed on laterally spaced horizontal axes extending longitudinally of the machine with radially elongated cutter arms having cutter devices thereon for cutting contiguous bores in advance of the machine, an axially elongated cutter bar horizontally disposed generally tangentially to the lower cutting limits of said cutter arms and spaced rearwardly of the circular paths of said cutter arms to cut a substantially flat transverse surface, said cutter bar being supported by said frame transversely to each side of vertical planes common with the axes of the drive shafts, drive means for said cutter bar supported on said frame, and at least one driving connection between said drive means and the cutter bar connected to the cutter bar intermediate the ends thereof, saiddriving connection being disposed in one of said vertical planes and within the cutting limit of the corresponding cutter arm.

References Cited in the tile of this patent UNITED STATES PATENTS 504,179 Stanley Aug. 29, 1893 556,985 Hurd Mar. 24, 1896 588,929 Raymond Aug. 24, 1897 847,801 Mott Mar. 19, 1907 1,148,976 Kuhn et al. Aug. 3, 1915 1,173,158 Arden Feb. 29, 1916 1,431,857 Willcox Oct. 10, 1922 1,588,563 Wilson .Tune 15, 1926 1,603,621 McKinlay Oct. 19, 1926 1,645,007 Johansen Oct. 11, 1927 1,659,942 Carlson Feb. 21, V1928 1,726,963 McKinlay Sept. 3, 1929 1,762,154 Blair June 10, 1930 1,808,649 Fleming June 2, 1931 1,834,587 Halleck Dec. 1, 1931 1,911,895 Hemscheidt May 30, 1933 2,445,957 Lindgren July 27, 1948 2,546,669 Kirby Mar. 27, 1951 2,548,952 Crossland Apr. 17, 1951 2,550,202 Robbins Apr. 24, 1951 2,612,346 Nelson Sept. 30, 1952 2,642,981 Lindgren June 23, 1953 2,695,700 Lindgren et al Nov. 30, 1954 FOREIGN PATENTS 900,445 France Oct. 2, 1944 

